Vascular endothelial growth factor (VEGF), its receptors (VEGFR-1, VEGFR-2) and neuropillin-1 (NRP-1) are expressed at variable levels in bone marrow. NRP-1expression is higher in fatty bone marrow than in hematopoietic marrow. Adipocytes are responsible for NRP-1 expression suggesting that they may play a role in hematopoiesis by producing NRP-1 or that NRP-1 may regulate adipocyte activity. [less ▲]